The Big Bang Theory's Simon Helberg on Growing Up

Ahead of the season finale, "The Big Bang Theory" co-star Simon Helberg speaks to WSJ's Alexandra Cheney on his character Howard's emotional growth spurt.

This transcript has been automatically generated and may not be 100% accurate.

I ... high end of the eighteen yen on St ... I'm here today with time and how that plays Howard Weil it on ... again ... Stephen Hawking's team is having an expedition to the North Sea that as I don't dynamic simulations black holes ... I know ... who the season finale and the big bang theory is coming up ... over the Christmas season you have been forced to grow up ... yes you ... started the season living ... with their mother I am ... and new lives into a number ... with your white ... mostly muscle he can ... and SA ... you ... have become kind of this change and Pfizer enter poly ... one of their house numbers is seeking insights how intense that change ... in your life changer character ... well I mean ... yet he spends the and ... basically ... flying ... seasonings and just as the stunted this man ... and he still stunned that the fishy certainly turn over a new leaf he was ... and a failed with Arielle and that ... he found ... the one and not just the one that no one girl that would tolerate ... and essentially so that ... he is that he has descended to the to settle down in the issue is the still get ... a foot Mehdorn as moms probably more than a few pairs of ... underwear he did season ... um so yet now it sits ... in some ways he's done a bit of a ... oh one eighty pound ... who would of thought that ... that that diet when would that ... be the most successful and love them so ... the acronyms ... it was a shocker thing to tell ... one of things that changed I think the status of play was your humor ... you were a lot more are ... candid and open and ... I think prior to brand that she's she's calms you down a level that what is that mean for our ... shoot burning it has definitely ... grounded him a bit better ... and he's he's ... he's not ... growing up anytime soon he's still pretty ... he's still learning now yes to just learn a whole new set of rules which is about ... marriage and I mean these are all little boys that can take baby steps and granted he did go ... probably the furthest that to the most baby steps still certainly all the fun of that character is is still there is just a token of different doors ... all ... really all about boys being boys ... he now but you aren't even know you're ... white you quickly our dependency turning into the man of the rally at the end ... of the ball and yet ... scary ... howling mad straining your relationship ... with the ball ... well I mean and I think he's seen a little bit of it ... with ... and ... for poly their their romances are taken a backseat ... to Howard's marriage nom ... but it still seems like ... Bernadette knows the priorities he knows ... that there will be ... the Indy nights in Halo nights and ... you know Howard still ... think the strain and ... I think that's what is being managed slowly signed ... spend ... thousands of dollars on a three D printer to make ... when models of himself and her and it was her money you spend a lot they shared and ... some in there there's some strain but ... again I think it ... actually opens the door for more ... um ... aam the isthe was the kind of ... changing the dynamic so drastically that it becomes a different shell or something ... what is your invites her a lot and as ... many as we can balance the finale in there as the worst bought late last year going and if they if they are really spotlight this year ... as you enter and that I'd you know several months apart ... what would your advice be for that ... we're going to be apart for months on yet ... I'm ... that that is is gearing up ... to look like that so so yeah I think the ... day I mean ... you know Howard Hughes in space ... couldn't quite escape his problems to ... his mother followed him to space via Sky basically and ... Hino and Jiechi ran away from dealing with that stuff so ... I mean ... I don't know what the reception is like out on the North Sea the ... time I'm sure that ... Leonard and Penny will will be communicating in ... any anything they've they've ... they've been doing well though I I don't know if I a ... they haven't they've kind of caught up so I would say ... I just hope that they ... communicate enough um ... and and maybe you know that when it can stand at the arms of ... as captain or or ... whoever whatever temptations around ... a few Fed has scripted Annie seen Acu sidestepped any scene for Howard ... what with what would you ... I mean I'm interested to see where ... the dynamic with his with his father ... and ... will ... will take to say you know whether you'll get to meet him ... an eight points or ... whether the father will ... try to contact him again aam ... that interest me ... a lot ... lastly what do you think ... just ... as a ... human being not necessarily how I think the first off I think you can compete for an amusing ... that era that Morsi main elements of the show that have resonated across such a wide audience because I think there are certain things in the show ... like ... people may not know what T E R Frank ... I don't either ... um I mean I think that these are ... their very grounding character is you know ... there are moments that are larger than life for them there it's outfits occasionally alert whom lifted their very ... we try to play them very real ... and ... I think the reason very real ... and that I think that it really is a story about ... these underdogs you know not having a manual ... for life trying to figure out a fat and being geniuses in one area and completely inept ... in another I think people can relate ... to that of all time and think you are cutting back on Wall Street Journal